Automatic stoker



(N0 Mqdel.) 2 Sheets-Sheet 1.

A. M. GOW. AUTOMATIC STOKE-R.

No. 449,157. Patented Mar. 31, 1891.

wrrnsssss mvnron v I No Model.) 2 Sheets-Sheet 2.

A. M. GOW. AUTOMATIG STOKER.

No. 449,157. Patented Mar. 31,1891.

WITNESSES INVENTOR UNITED STATES PATENT OFFICE.

ALEXANDER M. GOIV, OF PITTSBURG, PENNSYLVANIA.

AUTOMATIC STO KER.

SPECIFICATION forming part of Letters Patent No. 449,157, dated March 31, 1891. Application filed February 1, 1890. $erial No. 338.848. (N0 model.)

To all whom it may concern:

Be it known that I, ALEXANDER M. Gow, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Automatic Stokers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a front elevation of a furnace provided with myimproved apparatus. Fig. 2 is a vertical longitudinal section on the line II II of Fig. 1. Y 1

Like symbols of reference indicate like parts in each.

In the accompanying drawings, 2 represents the combustion-chamber of a furnace, which, as shown, is used in connection with a steam-boiler; butitwill be understood that my improved automatic stoker is of general application, and may be used with furnaces differentlyconstructed and employed forother purposes.

' 3 3 are stationary grate-bars, which are arranged in parallel series at successively lower planes, and are supported at the ends by side bearing-bars 4, one of which is shown in Fig. 2.

5 5 are the movable grate-bars or pusher-s, which are arranged alternately between the stationary bars, and are supported at the ends by a movable frame composed of bearing-bars 6. The shape in cross-section of the gratebars is clearly illustrated in Fig. 2. Each has a longitudinal strengthening-rib and a flat top portion with a downwardly-projecting lip at its edge. The top portions of the bars overlap each other, as shown in the drawings, and together the grate-bars form an inclined surface for the support of the fuel. The movable bearing-bars 6 are supported by links 7, which are pivoted thereto at the ends a, and at the other ends I) to brackets projecting downwardly from the fixed bearing-bars, so that the movable bearing-bars are capable of a longitudinal motiouwith radial motions of the links.

At the lower end of the series of grate bars is a dumping-grate section 8, whichis pivoted at c to the stationary side bearing-bars 4, and is provided with an operatingrod 9, which projects to the exterior of the combustion chamber and affords means by which the grate-section maybe overturned to dump the ashes therefrom into the ash-pit below.

As thus constructed, the operation of the apparatus is as follows: The coal is fed into the combustion-chamber at the higher end of the series of grate-bars, and from time to time, as frequently as may be necessary, it is fed forward and downward by imparting to the immovable side bars 6 a reciprocating motion, thus causing the grate-bars 5 to move laterally over the surfaces of the fixed bars 3. In this motion of the bars 5 their edges push forward the coal on the stationary grate-bars and cause it to advance gradually down the inclined surface of the bars to the dumping-section 8, during which advance it is consumed. The operation of my grate in thus with a lateral positive action pushing the coal from one end of the grate to the other forms one of its distinguishing and valuable characteristics, since clinkers are forcibly dislodged from the bars, the grate is kept clear, and the usual manual operation of stoking is performed mechanically in the best possible manner. During the forward motion of the movable bars the lips thereof serve to clear the clinkers from the stationary bars, and during their back motions the lips on the stationary bars serve to clear the clinkers from the surfaces of the movable bars. The advantages resulting from the invention in respect of the thoroughness of combustion of the coal and economy in its use will be appreciated by those skilled in the art.

It will be understood that mechanism of different forms of construction may be employed to operate the movable grate-bars in the manner above described, and that, although the mechanism shown in the drawings possesses many features of advantage which I intend to claim specifically herein, I do not intend to limit thereto the claims relating solely to the grate-bars constructed as above described. Said mechanism is thus constructed and arranged.

1O 10 are rods, which are attached to the movable side bars 6 and project to the outside of the combustion-chamber. They are connected at their ends by a cross-bar 11. A screw 12 passes through a nut in the bar 11 and is provided at its inner end with a head 13. By projecting or retracting the screw the extent of motion of the movable gratebars may be regulated, as hereinafter set forth.

2i is a rock-shaft, from which proj eet leverarms 14:, 15, and 16. The arm let has a looped portion encircling the screw-rod 12, the arm 15 has a looped portion encircling the piston 17 of a steam-cylinder 18, and the arm 16 has a similar looped portion encircling a rod 19, which forms part of the coal-feeding mechanism. Each of these arms has therefore a certain loose motion on its rod, the extent of which is limited adj nstably in case of the arm 1% by the head 13, in case of the arm 15 by a nut 20 on the piston-rod, and in caseof the arm 16 by a nut 21 on the rod 19. The reciprocation of the piston during a certain part of its stroke causes the reciprocation of the side bars 6 and of the movable grate bars, and the extent of such reciprocation may be adjusted accurately in the manner just mentioned. The rapidity of stroke of the piston is also regulable by proper variation in the admission of steam, so that the action of the grate-bars may be made to conform in frequency and extent to the conditions of the furnace and the nature of the fuel employed.

I shall now describe the mechanism for feeding the coal to the furnace.

22 is a hopper for receiving the coal-slack or other fuel. At its base is an opening which leads directly into the combustion-chamber and is closed by a door or valve .3, which is loosely mounted on the shaft 2i and is provided with the projecting rod 19, above mentioned. This door is oscillated to an adjustable extent by the rocking of the shaft 24, and at each back-stroke it allows a portion of the slack in the hopper to fall upon the slide or chute 25 at the entranceto the combustionchamber, and as the door has not only a horizontal portion (1 closing the bottom of the hopper, but a vertical portion 6, which closes the lateral opening into the combustion-chamber, the forward motion of the door serves to pushinto the combustion-chamber the slack which in its backstroke has been permitted to fall. This feeding mechanism is very reliable in its action, and as it completely shuts off the combustion-chamber from the hopper and prevents access of flame to the coal in the latter, a serious difficulty which is incident in the operation of other fuel-feeding devices is obviated.

The parts of my improved mechanism may be varied in divers ways w1th1n the scope of my invention.

Instead of producing the relative lateral movement of the grate bars by using one stationary set of bars and one reciprocatory set, both sets may be constructed to reciprocate in opposite directions to produce a similar result.

I claim- 1. The combination of a eombustion-cham-- ber, an inclined grate composed of movable bars arranged to cause the fuel to progress down the incline, a feed-hopper communicatin g with the combustion-chamber, and a hopper-botto1n movable to and from the opening from the combustion-chamber to the hopper and delivering the fuel through said opening to the upper end of the incline, said hopperbottom being mechanically connected with the grate-bar mechanism and movable therewith, the extent of motion communicated being sufiicient to move the hopper-bottom on its pushing-stroke to said opening to close the same, substantially as and for the pu rposes described.

2. The combination, with movable gratebars, of a piston for operating the same, a rock-shaft, and levers connecting the pistonrod with the rock-shaft and with the gratebars and having loose connections therewith, and mechanism by which the extent of loose motion is regulable, substantially as and for the purposes described.

3. The combination, with a combustionehamber having a projecting slide or chute 25, of a feed-hopper communicating with the combustion-chamber, and a movable hopperbottom having a portion d closing the base of the hopper and a portion a closing the opening into the combustion-chamber and serving at the same time to push the coal forward on the slide or chute into the combustion-chamber, substantially as and for the purposes de scribed.

i. The combination, with a movable grateframe, of an oscillatory rock-shaft adj ustably connected therewith, a movable hopper-bottom supported on said shaft and adj ustably connected therewith, substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand this 29th day of January, A. D. 1800.

ALEXANDER M. GOW. Witnesses:

\V. B. CORWIN, J NO. K. SMITH. 

